The bearings and bearing housings used in turbomachinery, such as gas turbines, are often located in a high temperature, high pressure environment. For example, when a bearing support is used between the compressor and turbine, the housing surrounding this bearing may be exposed to compressor discharge air which may be as hot as 600.degree. F or higher. If the fluid used to lubricate the bearing is exposed to this high temperature, it may deteriorate, forming coke or sludge. Such deterioration may also form a combustible mixture or emit vapors having a low self-ignition temperature. For these reasons, it has heretofore been common practice to insulate the wall surface forming the sump chamber from the high temperature environment, for example, by providing one or more surrounding chambers which may be supplied with a source of cooling air. It has also been the practice to provide an oil spray arrangement to which lubricating fluid is delivered in parallel with the flow of lubricating fluid to the bearing. While such arrangements can be effective, they require additional lubricating fluid flow rate capacity over that which is required by the bearing for lubrication purposes only and they tend to become somewhat complex.
The objective of the present invention is to provide an effective arrangement for cooling the bearing sump of a gas turbine. A further objective of the present invention is to provide a gas turbine bearing sump cooling arrangement which does not require an increase in overall lubricating fluid flow rate.